[problems]

Interesting, I often drop caffeine for a week or so (without any real conceited effort, typically just when I'm sick or on vacation) and any withdrawal seems gone after a few days but then restart it within a week because it's just so damn good, especially when you only sleep 4-6 hours a night which is... every night for me.

[jogundas]

The difference in the experiences of you two might be due to https://en.wikipedia.org/wiki/CYP1A2 aka "the caffeine gene".